Viessmann Vitodens 100-W
The Vitodens 100-W is Viessmann's main combi, built around a stainless steel heat exchanger. It is a compact wall-hung boiler with a long warranty when it is registered and serviced.
Who a Viessmann vitodens 100-w suits
Suits
- Houses with one or two bathrooms
- Buyers who want a stainless steel heat exchanger
- Homes where a compact boiler matters
Good points
- A long warranty on registration
- A stainless steel heat exchanger
- Compact wall-hung design
Watch out for
- Fewer installers know the make than know Worcester or Vaillant
- Costs more than the entry ranges
What a Viessmann vitodens 100-w costs
A Viessmann vitodens 100-w typically costs £2,800 (Viessmann Vitodens 100-W combi, fitted), with most jobs between £2,200 and £3,300. That includes VAT at 20%. Fitting takes 1–2 days on site.
What you would actually pay
Typical Viessmann Vitodens 100-W combi, fitted · UK- Typical installed cost Viessmann Vitodens 100-W, supplied and fitted
- £2,333
- VAT at 20% Standard rate
- £467
- Net cost to you
- £2,800
If you borrowed £2,800.00 over 36 months at 0.0%, it would cost £77.78 a month – £2,800.00 in total, of which £0.00 is interest. The last payment would be £77.70.
Illustration only – not a quote, not an offer of credit, and not financial advice. Rates depend on your circumstances and creditworthiness.
Where the money goes on a Viessmann vitodens 100-w
| Element | Typical range |
|---|---|
| Boiler and fitting The boiler at its published price, plus fitting by a Gas Safe engineer. This row is the headline price and covers the range. | £2,200 – £3,300 |
| Boiler only The boiler on its own, before fitting, shown so you can compare it with a retailer price. Included in the headline row. | £1,200 – £1,400 |
| Moving the boiler New pipework and a flue route where the boiler moves. Optional, and the labour grows with the distance. | £400 – £1,000 |
| Power flush Cleaning the radiators and pipework before the new boiler goes on. Optional, and worth asking about on an old system. | £400 – £700 |
| Magnetic filter Catches the iron sludge that wears out a boiler, and many manufacturers ask for one under their warranty terms. | £120 – £200 |
| Smart thermostat A programmable or smart thermostat in place of the old wall control. Optional, and sometimes offered free by the installer. | £140 – £300 |
Guide prices including VAT. Your actual cost depends on your home, access and specification.
What moves the price of a Viessmann vitodens 100-w
- The boiler itself
Budget ranges cost the least, mid-range ranges sit in the middle, and premium ranges with longer warranties cost the most. Output matters less to the price than the range does.
- Output
The same range comes in several outputs. A bigger output costs a little more, and a fitter should size it from the number of bathrooms and radiators, not from habit.
- Like for like or a conversion
Swapping a boiler for the same type in the same place is the cheapest job. Changing type, moving the boiler or re-routing the flue adds pipework, labour and days.
- The state of the system
Old radiators and pipes full of sludge can need a power flush, new valves or a filter before the installer will fit a new boiler under warranty.
- Where you live
Installer rates are higher in London and the South East than in the North and in Scotland, and the regional pages show the difference.
- Who fits it
National installers and local Gas Safe engineers quote differently for the same boiler. Compare quotes on the make and model, the warranty and what is included, not on the headline price alone.
What a quote for a Viessmann vitodens 100-w should include
If a quote is missing any of these, ask why before you compare it with another.
- The make, model and output of the boiler, and the length of the manufacturer warranty once it is registered
- Whether the price includes a magnetic filter, a system clean or flush, and the cost if the installer finds the system needs one
- Whether the flue, the condensate pipe and any new pipework are included, and what a longer or relocated flue adds
- Removal and disposal of the old boiler, and who registers the installation with Gas Safe and the manufacturer
- A fixed price in writing, the deposit and the payment schedule, and the workmanship guarantee
- The date, the number of engineers and how many days the heating and hot water will be off
Viessmann Vitodens 100-W prices by region
Labour is most of the difference. Typical price (Viessmann Vitodens 100-W combi, fitted), including VAT.
| Region | Typical | vs UK average |
|---|---|---|
| London | £3,500 | +25% |
| South East | £3,300 | +17% |
| South West | £3,100 | +10% |
| East of England | £3,000 | +6% |
| West Midlands | £2,900 | +4% |
| Scotland | £2,900 | +2% |
| East Midlands | £2,800 | UK average |
| Yorkshire and the Humber | £2,800 | UK average |
| North West | £2,700 | −2% |
| North East | £2,700 | −5% |
| Wales | £2,600 | −6% |
| Northern Ireland | £2,500 | −12% |
Common questions about a Viessmann vitodens 100-w
Is this the installed price?
It is built from the published boiler price and a typical fitting range, because the sources give the two separately. Treat it as a guide, and compare it with a written quote.
Does the warranty depend on who fits the boiler?
Often. Manufacturers usually ask for the boiler to be fitted by an approved installer, registered, and serviced every year to keep the longer warranty.
Is VAT charged on a new gas boiler?
Yes. Gas boilers are standard-rated, so the price shown includes VAT. The zero rate for energy-saving materials applies to heat pumps, solar panels and insulation, not to gas boilers.
Where these a Viessmann vitodens 100-w prices come from
Guide prices are compiled from published UK price guides, converted to a price before VAT, and shown here with VAT added. They are indicative, not quotations. How we price explains the method.
- greatbritishenergy.com, new boiler cost guide, updated 30 October 2026, quoting Checkatrade fitted prices and Which? brand prices (gas boilers standard-rated at 20%; the page does not say whether its figures include VAT, so they are treated as including it and divided by 1.2)
- Boiler Guide, combi boiler cost guide, updated 9 April 2025, for outputs by range
Worcester Bosch, Vaillant and Viessmann are trade marks of their respective owners. CombiBoiler.net is independent and is not affiliated with, sponsored or endorsed by any manufacturer. We name brands only to help you compare like with like; see how we make money.
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